Strict emission standards for internal combustion engines require the use of advanced fuel and reductant metering techniques that tightly control fluid doses. The fine atomization of fuel or reductant injected into the combustion chamber or exhaust stream, respectively, of the internal combustion engine not only improves emission quality of the engine's exhaust, but also improves fuel consumption, cold start capability, and overall engine performance. One way of injecting a fine spray into the engine's intake manifold, combustion chamber or exhaust stream is for the fluid to have a swirl flow pattern as the fluid exits the fluid injector.